For the third time since last week, a handful of Jewish students with Israeli flags was surrounded by demonstrators shouting anti-Semitic epithets and – according to two of the students – a tense minute of “pushing and shoving.”

Soon after the “die-in” ended, Brett Loewenstern — a Berklee College of Music student and pro-Israel activist – entered the fray with his boyfriend, Israeli-born Avi Levi.

According to Loewenstern, he and his boyfriend’s combining of an Israeli flag with a rainbow flag – the symbol for gay rights – set off a hailstorm of insults from demonstrators.

Among other things, the shouts included “Jews back to Birkenau” and “Drop dead, you Zionazi whores,” said Loewenstern and other witnesses.

Police had to extract the pair from among the demonstrators. The incident occurred at last Saturday’s “die-in” on the Boston Common, where anti-Israel demonstrators fell to the ground as protest leaders read the names of Palestinians killed in Gaza since the beginning of the most recent conflict.

As I wrote last week, the conceit that characterizes so many of these protests is that they are merely about borders and territory, war and peace — that they are political protests. But the ease with which “anti-Israel” protesters spew lines such as “Jews back to Birkenau” suggests that opponents of the Jewish state are often averse to Jews themselves.